Nebraska should be really good in Nickel or Dime packages this season. Here's why:
1. Kalu is a good tackler and better vs the run than even Gerry. As a corner, he was occasionally exposed vs bigger #2 wideouts. In passing situations, he's more slated for covering up the slot.. This allows Aaron Williams to play on the back end, blitz, or focus on a back. Kalu will become the primary Nickel. Williams was a decent Nickel, but his skill set was kind of wasted in man up coverage.
2. Kieron is average vs the run and in pursuit, but he has tremendous ball skills. He's extremely well prepared and instinctual when the ball is in the air. He won't play often on early Downs vs run heavy or power teams, but will be able to play a Free Roaming Safety in Nickel or vs pass happy Spread teams. With Kalu playing Nickelback in those situations, Kieron will be able to make plays on the back end. The stat from PFF illustrates his ability to make plays in pass defense.
I think Diaco spotted this right away and saw it as a way to beat use his team's skill set. I also believe they forsee Lamar Jackson making a jump at Corner.